The narwhal's tusk is a sensory organ — containing 10 million nerve endings that detect temperature and salinity.

Some mammals hibernate during winter.

Fact #303 · Animals

Some animals use echolocation to navigate in darkness.

Fact #278 · Animals

Clownfish can change sex during their lifetime.

Fact #361 · Animals

Some species of ants can form bridges using their bodies.

Fact #420 · Animals

A blue-ringed octopus carries venom potent enough to affect humans.

Fact #370 · Animals

Some birds migrate thousands of miles each year.

Fact #77 · Animals

A porcupine raises quills as a defense mechanism.

Fact #524 · Animals

Some snakes can sense heat using specialized pits.

Fact #408 · Animals